#include<stdio.h>
int main()
{
    int  a,i,m;
    printf("There are following perfect numbers smaller than 1000:\n");
    for(a=1;a<1000;a++)
    {
        for(m=0,i=1;i<=a/2;i++)
            if(!(a%i))
            m+=i;
        if(m==a)
        printf(" %4d\n",a);
    }
}